330 EXPERIMENT STATION RECORD. 



Nodules developed readily and continuously in light, but still more in dark- 

 ness, also readily in soil extract and in synthetic nutrient solutions in which 

 nitrates were either omitted or replaced by chlorids, but in a full nutrient solu- 

 tion containing nitrates continual development seems to be inhibited soon after 

 inoculation. No nodule development takes place in nutrient solutions in which 

 the individual essential elements are omitted, except in the case of nitrogen. 

 In sandy soil the optimum moisture content was from 20 to 40 per cent. The 

 addition to sandy soil of small percentages of peptone or of KNos, Ca(N03)2, 

 NHiCl, FeCls, or KCl inhibited nodule development, while the addition of tannic 

 acid or of MgSO*, KH2PO4, or Ca(H2P04)2 showed a beneficial effect. 



Nutrition markedly influences the morphology of the nodule organisms. The 

 effects are described of several media and modifications thereof, as employed. 

 The infecting power of B. radicicola on field pea was not affected after 2A years 

 on a given medium in the laboratory, the culture being transferred each month. 

 It was not appreciably influenced by nitrogenous or other media, all living cul- 

 tures producing nodules. In some media and under certain conditions the 

 organisms died sooner than in other media. Detection of infecting power is 

 comparatively easy, but accurate comparative measurement thereof is not yet 

 possible. 



A bibliography is given. 



Neg'ative heliotropism of the urediniospore germ tubes of Puccinia rhamni, 

 F. D. Fromme (Abs. in Phytopathologi/, J, {191J,), No. 6, pp. -}07, j^OS).— The 

 author reports that when germinating urediniospores of P. rhamni were ex- 

 posed to a unilateral diffused illumination during four or five hours, more than 

 80 per cent of the germ tubes grew away from the direction of the light. These 

 negative heliotropic reactions are thought possibly to play an important part 

 in bringing about the stomatal entrance of the germ tube. 



riora of Vermont {Vermont Sia. Bui. 187 {1915), pp. 139-258) .—This con- 

 sists of a list, prepared by a committee of the Vermont Botanical Club, of the 

 ferns and seed plants found growing within the State without cultivation. 



FIELD CROPS. 



Field experiments, 1914 {Dept. Agr. and Tech. Instr. Ireland Jour., 15 

 {1915), No. 2, pp. 247-317). — Results of variety tests with barley, potatoes, 

 mangels, oats, turnips, and wheat are reported. 



As a result of several years experiments in fertilizing meadow hay, it is noted 

 that applications of 10 tons of barnyard manure per acre gave satisfactory 

 results, but good returns were also obtained from the use of 100 lbs. of nitrate 

 of soda, 200 lbs. superphosphate, and 200 lbs. kainit per acre. The superphos- 

 phate and kainit were applied together before the end of February and the 

 nitrate at the end of March or early April. The application of kainit in the 

 fall often gave better yields, but not suflficient to warrant the cost of the 

 separate application. Basic slag is noted as giving better results in a wet 

 season than in a dry. Liquid manure was found to give excellent results with 

 all hay crops in both wet and dry seasons. The standard mixture of fertilizer 

 above mentioned is also recommended for peat soils. 



With potatoes, the best results were obtained by the use of 100 lbs. sulphate 

 of ammonia, 400 lbs. superphosphate, and 100 lbs. muriate of potash in the row 

 in connection with a moderate use of barnyard manure. It is noted that 

 manurial experiments with potatoes on peat soils are in progress. 



Experiments in the use of seaweed at the rate of 15 tons per acre as a fer- 

 tilizer for potatoes showed that " weight for weight, seaweed seldom produces 



